Metronidazole (or “Flagyl”) is a synthetic antibacterial and antiprotozoan antibiotic having the formula 2-methyl-5-nitroimidazole-1-ethanol. The antibiotic has been used for many years in its oral or intravenous form, to treat inflammatory conditions of the colon, rectum, anal canal and perianal region. Oral metronidazole has been traditionally used to treat inflammatory bowel disease (including Crohn's disease and ulcerative colitis), idiopathic proctocolitis, or radiation proctitis. In addition, the oral form is used to treat inflammatory conditions of the perianal region or anal canal such as anal fissures, fistulas, abscess, ulcers or post-surgical wounds. Metronidazole is also used in an intravenous form to treat systemic sepsis resulting from several inflammatory conditions of the colon and rectum.
Metronidazole possesses not only anti-bacterial properties, but also anti-inflammatory properties, which are less well understood. The medication is used for its anti-inflammatory properties in the treatment of several skin diseases.
Metronidazole is frequently associated with a number of serious side effects, both in its oral and intravenous form. These include GI manifestations, such as nausea, vomiting, a metallic taste in the mouth, or inflammation of the oral cavity. Serious neurological side effects can occur which usually manifest as numbness or tingling of the extremities. These neurological side effects can be debilitating, are often irreversible, and necessitate stopping the Metronidazole. Serious hematological, cardiovascular, or renal complications are also common and can be life-threatening. In addition, the overgrowth of opportunistic organisms such as Candida can result from oral or intravenous metronidazole treatment. In addition, oral metronidazole can interact in an adverse manner with other medications, such as oral anticoagulants (e.g. coumadin), which can cause potentially fatal bleeding.
Topical metronidazole has previously been used for a number of skin conditions (e.g. rosacea) or as a topical vaginal preparation in the treatment of vaginal infections (e.g. trichomonas). These preparations are contained in a medium containing alcohol, which would result in stinging and burning when used in the perianal region or in the anal canal. As far as the inventor is aware, there is no disclosure of the direct application of metronidazole into the rectum or distal colon (as for example a suppository, foam or enema) in the treatment of inflammatory disease and no such preparation of metronidazole is commercially available.